Chlamydomonas mutants having paralyzed flagella will be used to investigate the roles of the extra-microtubular flagellar components in flagellar movement. Biochemical and electron microscopic cytochemical studies will be carried out on mutants which lack either the radial spokes or the central tubules and their associated sheath to determine how the radial spoke and the central sheath act in flagellar bend formation. Studies will also be carried out to determine what proteins and enzyme activities are contained in these structures and the nexin links and the inner and outer arms of the outer doublets. These studies will help elucidate how the individual flagellar components interact in the propagation and coordination of the flagellar beat. This information should also lead to a better understanding of the functioning of a number of other complex microtubular organelles --e.g., the mitotic spindle of dividing cells and the microtubular systems of neurons and developing cells -- which may have mechanisms of action also dependent upon interactions between microtubules and extra-microtubular linkage components. BIBLIOGRAPHIC REFERENCES: Witman, G. B., R. Fay, J. Plummer and G. Borisy. 1975. Studies on Chlamydomonas mutants lacking the radial spokes and the central sheath and tubules. J. Cell. Biol. 67: 458a. Cleveland, D.W., S.-Y. Hwo, M. D. Weingarten, G. B. Witman and M. W. Kirschner. 1975. Mechanism of action of tau protein in microtubule assembly. J. Cell Biol. 67: 72a.